摘要
本文以土壤养分和土壤线虫为研究对象,在科尔沁沙地25年固定沙丘上从不同坡位、不同土壤深度和灌丛的影响三方面开展土壤养分和土壤线虫群落时空分布格局研究。目的是探明植被恢复对土壤养分和土壤线虫群落分布格局产生的影响,利用线虫群落指示沙丘生态系统土壤的恢复机理。试验结果表明：
(1)随着固沙植物的栽培,沙丘土壤养分NO3--N、NH4+-N和全N的含量随着土层深度的增加而表现出降低趋势,0-5cm土层含量显著高于其余各土层。N03--N和NH4+-N的富集能够降低土壤pH值,并提高土壤EC值,对沙土改良具有重要意义。
(2)小叶锦鸡儿的栽植影响了土壤交换性K、Na、Ca和Mg的含量分布,并受坡位的影响较大；随着土层的加深,各交换性盐分含量均表现降低的趋势：灌丛对于交换性Na、Ca和Mg的富集效果显著,对交换性K的效果不显著。
(3)TOC、全N和全P的含量随着土层加深而减少,并且迎风坡的TOC、全N和全P含量高于顶坡和背风坡；灌丛下土壤TOC和全K的含量明显高于丛间土壤；灌丛下C/N的变化大于丛间。
(4)土壤微生物生物量碳在固定沙丘的不同坡位、不同深度均存在明显差异,表层土壤含量最高,随着土层加深,土壤微生物生物量碳有所减少；植物栽植有利于土壤微生物生物量的积累。
(5)在春季,迎风坡和坡顶土壤线虫的分布由上至下随着土层的加深数目减少；在夏季,各坡位0-5cm土层线虫数量较少,5-10cm较多,下层依次减少。不同坡位间土壤线虫数没有明显差异。食细菌线虫为科尔沁沙地固定沙丘土壤线虫的优势类群。优势属为丽突属(Acrobeles)和拟丽突属(Acrobeloides),其次是鹿角唇属(Cervidellus)和威尔斯属(Wilsonema)。
(6)多因素方差分析结果显示,在春季,土壤线虫各指标受坡位影响最大,其次是土深和灌丛；在夏季,土壤线虫各指标受土壤深度影响最大,其次是坡位和灌丛；坡位,灌丛和土深三者交互作用对TNEM,BF和FF影响显著。季节的变化对土壤线虫的TNEM, OP,TD,EI,BI, BF,λ和H'影响显著。
(7)除土壤中全钾的含量与土壤呼吸和土壤微生物碳无相关性外,其他各种养分元素含量的增加对土壤呼吸和微生物碳含量均有显著的促进作用,提高了微生物的繁殖能力和活力；土壤微生物的增加为土壤肥力的提升起到了积极的促进作用。
(8)土壤养分物质的提升对土壤线虫的总数、食细菌线虫数、食真菌线虫数和均匀度具有重要影响,主要受土壤有机碳、土壤氮素、交换性钾和交换性钠的影响。土壤呼吸与微生物碳量对线虫的影响春季大于夏季。
This study objective is to explore effects of plant on spatial distribution of soil nutrients and soil nematode community and to use nematode group to indice recovery mechanism of ecological system on sand dune. Soil nutrients and soil nematode community were researched in different slopes, different depths and shrub influences on Horqin sand land which were planted vegetation for fixing sand dune 25 years ago. The results showed that:
(1) Contents of NO3--N, NH4+-N and total N descreased with soil depth for fixing sand vegetation were planted on sand dune. Contents of soil nutrients at depth of 0～5cm were significantly higher than that in other soil layers. The enrichment of NO3--N and NH4+-N decreased pH value and increased EC value, and had an important significance.
(2) Exchangeable K, Na, Ca and Mg were influenced by planted Caragana microphylla, especially at different slopes. Every kind of exchangeable salt decreased with soil depth. Shrubs took significantly effects on enrichment of exchangeable Na, Ca and Mg, but no significance on exchangeable K.
(3) Contents of TOC, total N and total P decreased with soil depth, and they were higher at WS than at TS and LS. Contents of TOC and total K are significantly higher at US than at BS. Changing range of C/N at US is larger than that at BS.
(4) Microbial biomass carbon showed the significantly difference at different slopes and depths of stable sand dune, and the highest content of it was at surface layer. Microbial biomass carbon decreased with soil depth. Planting enhanced the accumulation of microbial biomass carbon.
(5) Soil nematode individuals decreased with soil depth at WS and TS in spring. But numbers of nematode were the most at depth of 5～10cm on three slopes in summer, and showed no significance among slopes. Bacterivoirs trophic group is the dominance in Horqin stable sand dune. Dominant genera are Acrobeles, Acrobeloides, Cervidellus and Wilsonema.
(6) Multi-factor ANOVA analyisis showed that the most important factor affecting nematode indices is slope in spring. Following that is soil depth and shrub, respectively. In summer, the most important factor is soil depth, and slope and shrub followed. Intereaction from slope, shrub and depth on TNEM, BF and FF are significance. Different seasons affect TNEM, OP, TD, EI, BI, BF,λand H'significantly.
(7) Every testing nutrient took a significant effect on soil respiration and microbial biomass carbon except total K, and enhanced the ability of reproduce and activity. Adding number of microbe was benefit to soil fertility greatly.
(8) Enrichment of soil nutrients affects the number of SNEM, BF, FF and the J'significantly. The main influence factors were TOC, TN, exchangeable K and Na. Effects of soil spiration and microbial biomass carbon on nematode community were more significant in spring than that in summer.
引文
[1]阿拉木萨,蒋德明(2008).科尔沁沙地两种典型乔灌木耗水特点.生态学报28(5)：1981-1990.
[2]阿拉木萨,蒋德明,等.(2007).科尔沁沙地典型人工植被区土壤水分动态研究.干旱区研究24(5)：604-609.
[3]阿拉木萨,裴铁瑶,等.(2005).科尔沁沙地人工固沙林土壤水分与植被适宜度探讨.水科学进展16(3)：426-431.
[4]包耀贤,吴发启,等.(2008).渭北早塬梯田土壤氮素特征及影响因素分析.干旱地区农业研究26(5)：109-114.
[5]曹成有,蒋德明,等.(2004).科尔沁沙地小叶锦鸡儿人工固沙区土壤理化性质的变化水土保持学报18(6)：108-111,131.
[6]曹成有,蒋德明,等.(2006).科尔沁沙地草甸草场退化的原因与植物多样性变化.草业学报15(3)：18-26.
[7]曹成有,刘世炎(2000).小叶锦鸡儿人工固沙区植被恢复生态过程的研究.应用生态学报11(3)：349-354
[8]曹成有,朱丽辉,等.(2007).科尔沁沙质草地沙漠化过程中土壤生物活性的变化.生态学杂志26(5)：622-627.
[9]曹成有,朱丽辉,等.(2007).科尔沁沙地不同人工植物群落对土壤养分和生物活性的影响.水土保持学报21(1)：168-171.
[10]常学向,赵爱芬,等.(2003).黑河中游荒漠绿洲区免灌植被土壤水分状况.水土保持学报17(2)：126-129.
[11]陈立杰(2003).施用农用化学品对农田土壤线虫群落产生的影响.中国科学院研究生院博士后研究工作报告.沈阳,中国科学院沈阳应用生态研究所.
[12]陈荣毅,张元明,等.(2008).不同沙丘部位和不同结皮类型对土壤种子库的影响.干旱区研究25(1)：107-113.
[13]陈四清(1999).内蒙古锡林河流域大针茅草原土壤呼吸和凋落物分解的CO2排放速率研究.植物学报41(6)：645-650.
[14]陈有鑑,黄艺,等.(2002).玉米和大豆根际土壤性质的动态变化.植物生态学报26(3)：283-287.
[15]崔骁勇,陈佐忠,等.(2001).草地土壤呼吸研究进展.生态学报21(2)：315-325.
[16]董锡文,张晓珂,姜思维,蒋德明,汪景宽.(2010)科尔沁沙地固定沙丘土壤氮素空间分布特征研究[J].土壤,42(1)：76-81
[17]董学军,陈仲新,等.(1999).毛乌素沙地沙地柏的水分生态初步研究.植物生态学报23(4)：311-319.
[18]冯志新(2001).植物线虫学.北京,中国农业出版社.
[19]郭轶瑞,赵哈林,等.(2008).科尔沁沙地沙丘恢复过程中典型灌丛下结皮发育特征及表层土壤 特性.环境科学29(4)：1027-1034.
[20]贺金生,王政权,等.(2004).全球变化下的地下生态学：问题与展望.科学通报49(13)：1226-1233.
[21]胡峰,李辉信,等.(1999).土壤食细菌线虫与细菌的相互作用以及对N、P矿化—生物固定的影响及机理.生态学报19(6)：914-920.
[22]蒋德明,曹成有(2008).科尔沁沙地小叶锦鸡儿人工林防风固沙及改良土壤效应研究.干旱区研究25(5)：653-658.
[23]蒋德明,刘志民,等.(2003).科尔沁沙地荒漠化过程与生态恢复.北京,中国环境科学出版社.
[24]拉木萨,慈龙骏,等.(2006).科尔沁沙地不同密度小叶锦鸡儿灌丛水量平衡研究.应用生态学报17(1)：31-35.
[25]李辉信,刘满强,等.(2002).不同植被恢复方式下红壤线虫数量特征.生态学报22(11)：1882-1889.
[26]李凌浩,韩兴国,等.(2002).锡林河流域一个羊草群落中土壤呼吸与生物量之问的相关性分析.植物学报44(5)：593-597.
[27]李雪华,韩士杰,等.(2006).科尔沁沙地不同演替阶段植被特征及固沙作用.辽宁工程技术大学学报25(5)：789-791.
[28]梁晨,吕国忠(2000).辽宁省农田土壤真菌区系及分类研究.沈阳农业大学学报3(5)：515-516.
[29]梁文举,葛亭魁,等.(2001).土壤健康及土壤动物生物指示的研究与应用.沈阳农业大学学报32(1)：70-72.
[30]廖崇惠,李健雄,等.(2003).海南尖峰岭热带林土壤动物群落.生态学报23(1)：139-147.
[31]刘方明(2006).小叶锦鸡儿人工林土壤线虫群落特征的研究.中国科学院研究生院博士学位论文.沈阳,中国科学院沈阳应用生态研究所.
[32]刘方明,郝伟,等.(2006).科尔沁沙地小叶锦鸡儿对土壤有机碳积累的影响.辽宁工程技术大学学报25(2)：294-296.
[33]刘建军,王得祥,等.(2003).秦岭天然油松、锐齿栎林地土壤呼吸与C02释放.林业科学39(2)：8-13.
[34]鲁如坤(2002).土壤农业化学分析方法.北京,中国农业科技出版社.
[35]吕殿青(2008).六道沟流域不同坡位不同土地利用方式下的土壤持水特征研究.中国农学通报24(8)：279-281.
[36]吕贻忠,李保国,等.(2002).鄂尔多斯不同地形下土壤养分的空间变异.土壤与环境11(1)：32-37.
[37]彭少麟,李跃林,等.(2002).全球变化条件下的土壤呼吸效应.地球科学进展17(5)：705-703.
[38]史小红,李畅游(2006).科尔沁沙地不同植被类型区土壤水分特性分析.云南农业大学学报21(3)：355-359.
[39]苏永中,赵哈林(2002).几种灌木、半灌木对沙地土壤肥力影响机制的研究.应用生态学报13(7)：802-806.
[40]苏永中,赵哈林,等.(2002).不同强度放牧后自然恢复的沙质草地土壤性状特征.中国沙漠22(4)：334-338.
[41]苏永中,赵哈林,等.(2002).农田沙漠化演变中土壤质量的生物学特性变化.干旱区研究19(4)：64-68.
[42]苏永中,赵哈林,等.(2004).科尔沁沙地不同年代小叶锦鸡儿人工林植物群落特征及其土壤特性.植物生态学报28(1)：93-100.
[43]孙波,赵其国,等.(1997).土壤质量与持续环境Ⅲ--土壤质量评价的生物学指标.土壤学报(5l225-234.
[44]王少昆,赵学勇,等.(2008).科尔沁沙地植物萌动期不同类型沙丘土壤微生物区系特征.中国沙漠28(4)：696-700.
[45]姚洪林,阎德仁,等.(2001).毛乌素沙地流动沙丘风蚀积沙规律研究.内蒙古林业科技1：3-9.
[46]叶冬梅,秦佳琪,等.(2005).乌兰布和沙漠流动沙丘不同部位水分动态研究.干旱区研究22(3):367-370.
[47]俞慎,李勇,等.(1999).土壤微生物生物量作为红壤质量生物指标的探讨.土壤学报36(3)：413-422.
[48]于顺利,蒋高明(2003).土壤种子库的研究进展及若干研究热点.植物生态学报27(4)：551-560.
[49]岳广阳,赵哈林,等.(2007).不同天气条件下小叶锦鸡儿茎流及耗水特性.应用生态学报18(10)：2173-2178
[50]张玲,叶正钱(2006)铅锌矿区污染土壤微生物活性研究.水土保持学报20(3)：136-140.
[51]张晓珂(2008).科尔沁沙地沙丘土壤线虫群落空间分布格局研究.中国科学院研究生院博士后研究工作报告.沈阳,中国科学院沈阳应用生态研究所.
[52]张晓珂,董锡文,梁文举等.(2009)科尔沁沙地流动沙丘土壤线虫群落组成与多样性研究[J].土壤,41(5)：749-7'56.
[53]张玉革,梁文举,等.(2008).不同利用方式对潮棕壤交换性钾钠及盐基总量的影响.土壤通报39(4)：816-821.
[54]张志山,谭会娟,等.(2005).沙漠人工植被区土壤呼吸初探.中国沙漠25(4)：525-528.
[55]赵哈林,根本正之,等.(1997).内蒙古科尔沁沙地放牧草地的沙漠化机理研究.中国草地17(增刊). 15-21.
[56]赵文智(2002).科尔沁沙地人工植被对土壤水分异质性的影响.土壤学报39(1)：113-119.
[57]赵学勇,贺丽萍(2002,).科尔沁沙地生态系统典型土壤养分空间分布特征.中国沙漠22(4)：328-332.
[58]赵学勇,左小安,等.(2006).科尔沁不同类型沙地土壤水分在降水后的空间变异特征.干旱区地 理29(2)：275-281.
[59]中国土壤学会农业化学专业委员会(1984).土壤农业化学常规分析方法.北京,科学出版社.
[60]周德庆(2002).微生物学教程,高教出版社.
[61]朱选伟(2004).浑善达克沙地几种优势植物的生态适应.中国科学院博士学位论文.北京,中国科学院植物研究所：1-7.
[62]朱震达,赵兴梁,等.(1998).治沙工程学.北京,中国环境出版社.
[63]Aitzetmuller, K., N. Tsevegsuren, et al. (1999). Seed oil fatty acid patterns of the Aconitum-Delphinium-Helleborus complex (Ranunculaceae). Plant Systematics and Evolution 215(1-4):37-47.
[64]Antunes, S. C., R. Pereira, et al. (2008). Spatial and temporal distribution of litter arthropods in different vegetation covers of Porto Santo Island (Madeira Archipelago, Portugal). European Journal of Soil Biology 44:45-56.
[65]ArmendaAriz, I., M. Hernandez, et al. (1996). Temporal evolution of soil nematode communities in Pinus nigra forest of Navarra Spain. Fundamental and Applied Nematology 19:561-577.
[66]Badiane, N. N. Y., J. L. Chotte, et al. (2001). Use of soil enzyme activities to monitor soil quality in natural and improved fallows in semi-arid tropical regions. Applied Soil Ecology 18(3):229-238.
[67]Belnap, J. (2003). The world at your feet:desert biological soil crust. Frontiers in Ecology and the Environment 1:181-189.
[68]Billings, S. A., S. M. Schaeffer, et al. (2003). Nitrogen fixation by biological soil crusts and heterotrophic bacteria in an intact Mojave Desert ecosystem with elevated CO2 and added soil carbon. Soil Biology & Biochemistry 35(5):643-649.
[69]Blackwell, M. S. A., J. K. Williams, et al. (2009). Significance of Root-Attached Soil and Soil Preparation for Microbial Biomass Phosphorus Measurement. Soil Science Society of America Journal 73(6):1861-1863.
[70]Bochet, E., J. Rubio, et al. (1999). Modified topsoil islands within patchy Mediterranean vegetation in SE Spain. Catena 38:23-44.
[71]Bongers, T. (1990). The maturity index:an ecological measure of environmental disturbance based on nematode species composition. Oecologia 83:14-19.
[72]Bongers, T. and M. Bongers (1998). Functional diversity of nematodes. Applied Soil Ecology 10(3): 239-251.
[73]Bongers, T. and H. Ferris (1999). Nematode community structure as a bioindicator in environmental monitoring. Trends Ecol Evol 14(6):224-228.
[74]Breemen, N. V. and F. A. C. (1998). Plant-soil Interactions:Ecological Aspects and Evolutionary Implications. Biogeochemistry 42:1-19.
[75]Brookes, P., D. Powlson, et al. (1982). Measurement of microbial biomass phosphorus in soil. Soil Biology and Biochemistry 14:319-329.
[76]Cadet, P., J. Thioulouse, et al. (1994). Relationships between ferrisol properties and the structure of plant parasitic nematode communities on sugarcane in Martinique (French West Indies). Acta Oecologica 15:767-780.
[77]Campo, J., J. M. Maass, et al. (2000). Calcium, potassium, and magnesium cycling in a Mexican tropical dry forest ecosystem. Biogeochemistry 49(21-36).
[78]Cao, C. Y., D. M. Jiang, et al. (2008). Soil chemical and microbiological properties along a chronosequence of Caragana microphylla Lam. plantations in the Horqin sandy land of Northeast China. Applied Soil Ecology 40(1):78-85.
[79]Charley, J. and N. West (1975). Plant-induced soil chemical patterns in some shrub-dominated semi-desert ecosystems of Utah. Ecol.63:945-963.
[80]Dong, X.W. Zhang, X.K. Bao, X.L. Wang, J.K.(2009) Spatial distribution of soil nutrients after the establishment of sand-fixing shrubs, on sand dune[J]. Plant Soil Environ.,55, (7):288-294.
[81]Ferris, H., T. Bongers, et al. (2001). A framework for soil food web diagnostics:extension of the nematode faunal analysis concept. Applied Soil Ecology 18(1):13-29.
[82]Freckman, D. (1988). Bacterivorous nematodea and organic matter decomposition. Agriculture,Ecosystems, and Environment 24:195-217.
[83]Freckman, D. and C. Ettema (1993). Assessing nematode communities in agroecosysterns of varying human intervention. Agricultural Ecosystem and Environment 45:239-261
[84]Freckman, D. and R. Virginia (1997). Low-diversity Antarctic soil nematode communities: distribution and response to disturbance. Ecology 78:363-369.
[85]Freckman, D. W., and R. A. Virginia.1998. Soil biodiversity, and community structure in the McMurdo Dry Valleys, Antarctica. Pages 323-336 in J. C. Priscu, ed. Ecosystem Dynamics in a Polar Desert. The McMurdo Dry Valleys, Antarctica. American Geophysical Union, Washington, DC.
[86]Garner, W. and Y. Seinberger (1990). Approposed mechanism for the formation of'fertile island'in the desert ecosystem. J. Arid Environ.16:257-262.
[87]Garner, W. and Y. Steinberger (1998). Approposed mechanism for the formation of 'fertile island' in the desert ecosystem. J. Arid Environ.16:257-262.
[88]Goede, R. D. and B. T (1994). Nematode community structure in relation to soil and vegetation characteristics. Applied Soil Ecology:29-44.
[89]Gromes, R., K. Mueller, et al. (2001). The use of photometric test kits for investigations of soil enzyme activities. Journal of Plant Nutrition and Soil Science-Zeitschrift Fur Pflanzenernahrung Und Bodenkunde 164(4):431-433.
[90]Gupta, V, G Yeates, et al. (1997). Soil Microfauna as Bioindicators of Soil Health. Wallingford, CAB International.
[91]Gupta, V., G. Yeates, et al. (1997). Soil microfauna as bioindicators of soil health. In:Pankhurst C, Biological indicators of soil health. International:201-233.
[92]Hansen, R. A. (1999). Red oak litter promotes a microarthropod functional group that accelerates its decomposition. Plant and Soil 209(1):37-45.
[93]Hansson, A. C., Z. Aifen, et al. (1994). Fine-root growth dynamics of 2 shrubs in semiarid rangeland in Inner-Mongolia, China. Ambio 23:225-228.
[94]Hansson, A. C., Z. Aifen, et al. (1995). Fine-root production and mortality in degraded vegetation in Horqin Sandy Rangeland in Inner Mongolia, China Arid Land Research and Managements 9:1-13.
[95]Hesp, P. and A. McLachlan (2000). Morphology, dynamics, ecology and fauna of Arctotheca populifolia and Gazania rigens nabkha dunes. Journal of Arid Environments 44(2):155-172.
[96]Hill, V. L. and G L. Florant (1999). Patterns of fatty acid composition in free-ranging yellow-bellied marmots (Marmota flaviventris) and their diet. Canadian Journal of Zoology-Revue Canadienne De Zoologie 77(9):1494-1503.
[97]Houghton FE Climatic guide, New Mexico State University, Las Cruces, New Mexico 1851-1971. New Mexico Agriculture Research Report,1972,230:1-20.
[98]Hook, P., I. Burke, et al. (1991). Heterogeneity of soil and plant N and C associated with individual plants and openings in North American shortgrass steppe. Plant Soil 138:247-256.
[99]Jiang, D. M., Q. Li, et al. (2007). Vertical distribution of soil nematodes in an age sequence of Caragana microphylla plantations in the Horqin Sandy Land, Northeast China. Ecological Research 22(1):49-56.
[100]Jobbagy, E. G. and R. B. Jackson (2001). The distribution of soil nutrients with depth:Global patterns and the imprint of plants. Biogeochemistry 53(51-77).
[101]Kandji, S. T., C. K. P. O. Ogol, et al. (2001). Diversity of plant-parasitic nematodes and their relationships with some soil physico-chemical characteristics in improved fallows in western Kenya. Applied Soil Ecology 18(2):143-157.
[102]Ladd, J. N., M. Amato, et al. (2004). Soil microbial biomass:its assay and role in turnover of organic matter C and N.Soil Biology & Biochemistry 36(9):1369-1372.
[103]Li, S. G., Y. Harazono, et al. (2002). Micrometeorological changes following establishment of artificially established Artemisia vegetation on desertified sandy land in the Horqin sandy land, China and their implication on regional environmental change. Journal of Arid Environments 52: 101-119.
[104]Liang, W., I. Lavian, et al. (2001). Diversity and dynamics of soil free-living nematode populations in a Mediterranean agroecosystem. Pedosphere 33:208-213.
[105]Liang, W. and Y. Steinberger (2001). Temporal changes in nematode community structure in a desert ecosystem. Journal of Arid Environments 48(3):267-280.
[106]Liang, W. J., S. Mouratov, et al. (2002). Seasonal variation in the nematode communities associated with two halophytes in a desert ecosystem. Pedobiologia 46(1):63-74.
[107]Liang, W. J., Y. Pinhasi-Adiv, et al. (2000). Nematode population dynamics under the canopy of desert halophytes. Arid Soil Research and Rehabilitation 14(2):183-192.
[108]Manlay, R. J., P. Cadet, et al. (2000). Relationships between abiotic and biotic soil properties during fallow periods in the sudanian zone of Senegal. Applied Soil Ecology 14(2):89-101.
[109]McSorley, R. and J. J. Frederick (2002). Effect of subsurface clay on nematode communities in a sandy soil. Applied Soil Ecology 19(1):1-11.
[110]Moore, J. and P. D. Ruiter (1991). Temporal and spatial heterogeneity of trophic interactions within below-ground food webs. Agriculture, Ecosystems and Environment 34:371-397.
[111]Morel, C. and P. Hinsinger (1999). Root-induced modifications of the exchange of phosphate ion between soil solution and soil solid phase. Plant and Soil 211(1):103-110.
[112]Moya, M., E. Cortes, et al. (1999). Stability of plasma and erythrocyte membrane phospholipids fatty acid patterns in preterm babies fed with or without arachidonic (AA) and docosahexaenoic (DHA) acids. Pediatric Research 45(4):287-287.
[113]Neher, D. (2001). Role of nematodes in soil heath and their use as indicators. Journal of Nematology 33(4):61-168.
[114]Nobrega, A., A. Grandien, et al. (1998). Functional diversity and clonal frequencies of reactivity in the available antibody repertoire. Eur J Immunol 28(4):1204-1215.
[115]Nombela, G., A. Navas, et al. (1993). Spatial and temporal, variation of the nematofauna in representative soils of the central region of the Iberian Peninsula. Nematologica 39(81-91).
[116]Okada, H. and H. Ferris (2001). Effect of temperature on growth and nitrogen mineralization of fungi and fungal-feeding nematodes. Plant and Soil 234(2): 253-262.
[117]Olafasson, E. and R. Elmgren (1997). Seasonal dynamics of sublittoral meiobenthos on relation to phytoplankton sedimentation in the Blatic Sea. Estuarine Coastal and Shelf Science 45:149-164.
[118]Pen-Mouratov, S., M. Rakhimbaev, et al. (2004). Spatial and temporal dynamics of nematode populations under Zygophyllum dumosum in and environments. European Journal of Soil Biology 40(1):31-46.
[119]Pen-Mouratov, S., M. Rakhimbaev, et al. (2003). Seasonal and spatial variation in nematode communities in a Negev desert ecosystem. Journal of nematology 35(2):157-166.
[120]Peredney, C. L. and P. L. Williams (2000). Utility of Caenorhabditis elegans for assessing heavy metal contamination in artificial soil. Archives of Environmental Contamination and Toxicology 39(1):113-118.
[121]Popovici, I. and, M. Ciobanu (2000). Diversity and distribution of nematode communities, in grasslands from Romania in relation to vegetation and soil characteristics. Applied Soil Ecology 14(1):27-36.
[122} Porazinska, D. L., R. D. Bardgett, et al. (2003). Relationships at the aboveground-belowground interface:Plants, soil biota, and soil processes. Ecological Monographs 73(3):377-395.
[123]Porazinska, L., R. McSorley, et al. (1998). Relationshios between soil chemical status, soil nematode community, and sustainability indices. Nematropica 28(2):249-262.
[124]Rossi, R. E., D. J. Mulla, et al. (1992). Geostatistical tools for modeling and interpreting ecological spatial dependence. Ecological Monographs 62:277-314.
[125]Schade, J. D. and S. H. Hobbie (2005). Spatial and temporal variation in islands of fertility in the Sonoran Desert. Biogeochemistry 73(541-553).
[126]Schloter, M., O. Dilly, et al. (2003). Indicators for evaluating soil quality. Agriculture Ecosystems & Environment 98(1-3):255-262.
[127]Steinberger, Y. and S. S (1993). Response by soil nematode populations in the soil microbial biomass to a rain episode in the hot, dry Negev desert. Biology and Fertility of Soils 16:188-192.
[128]Steinberger, Y., L. WJ, et al. (2001). Nematode community composition and diversity associated with a topoclimatic transect in a rain shadow desert. European Journal of Soil Biology 37(4): 315-320.
[129]Su, Y. Z., Z. H.L., et al. (2004). Influencing mechanisms of several shrubs on soil chemical properties in semiarid Horqin Sandy Land, China. Arid Land Research and Management 18: 251-263.
[130]Su, Y. Z., Z. T.H., et al. (2005). Changes in soil properties after establishment ofArtemisia halodendron and Caragana microphylla on shifting sand dunes in semiarid Horqin Sandy Land, Northern China. Environmental Management 36:272-281.
[131]Su, Y. Z. and H. F. Zhao (2003). Soil properties and plant species in an age sequence of Caragana microphylla plantations in the Horqin Sandy Land, north China. Ecological Engineering 20(3): 223-235.
[132]Thompson, D. B., L. R. Walker, et al. (2005). The influence of elevation, shrub species, and biological soil crust on fertile islands in the Mojave Desert, USA. Journal of Arid Environments 61: 609-629.
[133]Titus, J. H., R. S. Nowak, et al. (2002). Soil resource heterogeneity in the Mojave Desert. Journal of Arid Environments 52(269-292).
[134]Todd, T. C., J. M. Blair, et al. (1999). Effects of altered soil-water availability on a tallgrass. prairie nematode community. Applied Soil Ecology 13(1):45-55.
[135]Tornquist, C. G., F. M. Hons, et al. (1999). Agroforestry system effects on soil characteristics of the Sarapiqui region of Costa Rica. Agriculture Ecosystems & Environment 73(1):19-28.
[136]Van Breemen, N. and A. C. Finzi (1998). Plant-soil interactions:ecological aspects and evolutionary implications. Biogeochemistry 42(1-2):1-19.
[137]Venette, R. and H. Ferris (1997). Thermal constraints to population growth of bacterial-feeding nematodes. Soil Biology and Biochemistry 29(1):63-74.
[138]Viketoft, M., C. Palmborg, et al. (2005). Plant species effects on soil nematode communities in experimental grasslands. Applied Soil Ecology 30(2):90-103.
[139]Wall, D. H. and R. A. Virginia (1999). Controls on soil biodiversity:insights from extreme environments. Applied Soil Ecology 13(2):137-150.
[140]Wall, J. W., K. R. Skene, et al. (2002). Nematode community and trophic structure along a sand dune succession. Biology and Fertility of Soils 35(4):293-301.
[141]Wardle, D. (2002). Communities and ecosystems:linking the aboveground and belowground components Princeton, Princeton University Press.
[142]Wardle, D., G. Yeates, et al. (1995). The detritus food-web and the diversity of soil fauna as indicators of disturbance regimes in agro-ecosystems. Plant and Soil 170:35-43.
[143]Wardle, D., G Yeates, et al. (2003). The responses of a three trophic level soil food web to the identity and diversity of plant species and functional groups. Oikos 102:45-56.
[144]Wardle, D. A., R. D. Bardgett, et al. (2004). Ecological linkages between aboveground and belowground biota. Science 304(5677):1629-1633.
[145]Wardle, D. A., G. W. Yeates, et al. (1995). The detritus food-web and the diversity of soil fauna as indicators of disturbance regimes in agro-ecosystems. Plant and Soil 170:35-43.
[146]Wardle, D. A., G W. Yeates, et al. (2004). Linking aboveground and belowground communities:the indirect influence of aphid species identity and diversity on a three trophic level soil food web. Oikos 107(2):283-294.
[147]Wezel, A., J. Rajot, et al. (2000). Influence of shrubs on soil characteristics and their function in Sahelian agro. ecosystems in semi-arid Niger. J. Arid Environ.44:383-398.
[148]Whitford, W., J. Anderson, et al. (1997). Stemflow contribution to the'fertile island'effect in creosotebush, Larrea tridentate. Arid Environ.(35):451-457.
[149]Xie, G. H. and Y. Steinberger (2001). Temporal patterns of C and N under shrub canopy in a loessial soil desert ecosystem. Soil Biology and Biochemistry 33:1371-1379.
[150]Yeates, G and A. Bird (1994). Some observations on the influence of agricultural practices on the nematode faunae of some South Australian soils. Fundamental and Applied Nematology 17: 133-145,
[151]Yeates, G, T. Bongers, et al. (1993). Feeding habits in nematode families and genera-an outline for soil ecologists. Journal of Nematology 25:315-331.
[152]Yeates, G W., D. A. Wardle, et al. (1999). Responses, of soil nematode populations, community structure, diversity and temporal variability to agricultural intensification over a seven-year period. Soil Biology & Biochemistry 31(12):1721-1733.
[153]Zelles, L. (1999). Fatty, acid patterns of phospholipids and lipopolysaccharides in the characterisation of microbial communities in soil:a review. Biology and Fertility of Soils 29(2): 111-129.
[154]Zhang, T. H., Y.Z. Su, et al. (2006). A leguminous shrub (Caragana microphylla) in semiarid sandy soils of north China. Pedosphere 16:319-325.
[155]Zhang, T. H., H. L. Zhao, et al. (2004). A comparison of different measures for stabilizing moving sand dunes in the Horqin Sandy Land of Inner Mongolia, China. Journal of Arid Environments 58(2): 203-214.
[156]Zhang, X. K., Dong, X. W. et al. (2010). Spatial Distribution of Soil Nematode Communities in Stable and Active Sand Dunes of Horqin Sandy Land. Arid Land Research and Management 24(1): '68-80.
[157]Zhang, X. K., W. J. Liang, et al. (2007). Soil nematode community structure in a Chinese sand dune system. Helminthologia 44(4):204-209.
[158]Zhao, H. L., R. L. Zhou, et al. (2007). Shrub facilitation of desert land restoration in the Horqin Sand Land of Inner Mongolia. Ecological Engineering 31:1-8.
[159]Zuo, X. A., H. L. Zhao, et al. (Soil and Tillage Research). Spatial pattern, and heterogeneity of soil properties in sand dunes under grazing and restoration in Horqin Sandy Land, Northern China.2008 99:202-212.
